Hi Pushpa raj pandey,
Can you please tell me which model of Dell Inspiron N series you have? It would be much easier for me to help you about the issue.
However at present there are no Windows 8 drivers available for Inspiron N series laptops. You have to wait for some time to get Windows 8 drivers for Inspiron N series laptop.
However you can download and try installing Windows 7 drivers on your Windows 8 computer. Don’t forget to back up your data before installing the drivers. It’s not sure whether the drivers would work fine or not.
Hope this helps.